A three-level coordinated pressure-yielding energy-absorbing support system

Abstract

The invention belongs to the technical field of tunnel support, and specifically relates to a three-level coordinated pressure-yielding energy-absorbing support system. The pressure-yielding energy-absorbing anchor cable plays a basic supporting role, and the circumferential pressure-yielding device can make the primary support pressure-yielding arch frame undergo constant resistance deformation in the circumferential direction, while the primary support pressure-yielding arch frame and the secondary lining steel arch frame in the radial pressure-yielding device undergo relative dislocation movement, and the three-level pressure-yielding energy-absorbing structures cooperate with each other to adapt to the ultra-large deformation movement of the surrounding rock. The three-level support system stabilizes the large deformation pressure of the surrounding rock, and slowly performs the compression-resistant retraction of the primary support pressure-yielding arch frame, reducing the possibility of the compression-resistant arch frame locking structure being damaged due to the strong impact pressure of the displacement; effectively controlling the tunnel compression-resistant pressure and the expansion rate and deformation size of the tunnel surrounding rock extrusion deformation, so that the three-level support system can better adapt to the surrounding rock deformation, and also ensure that the three-level support system always effectively plays a good supporting role, thereby improving the safety of the entire support system and helping to reduce economic losses.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel support, and specifically relates to a three-level coordinated pressure-yielding energy-absorbing support system. Background Art

[0002] Crossing the rock mass of the fault fracture zone is a key node in tunnel construction. A major challenge is the large deformation of the surrounding rock. Due to the extreme fracture of the rock mass in the fracture zone and the complete development of cracks, the surrounding rock has a large deformation, a high deformation rate, a long convergence time, or even difficulty in convergence. Traditional support technologies mostly use a composite rigid support system of primary support and secondary lining. The primary support layer mainly includes anchor rods / cables, steel arch frames and concrete layers, and the secondary lining layer is mainly a reinforced concrete layer. The primary support layer and the secondary lining rely on sufficient stiffness and strength to resist the large deformation of the surrounding rock in the fracture zone. If the stiffness and strength of the primary support layer and the secondary lining are blindly strengthened, the primary support layer and the secondary lining will be subjected to great stratum pressure under the action of high ground stress in the fault fracture zone, which can easily cause concrete damage, steel arch frame distortion, faulting, invert arch uplift, and secondary lining cracking. The support system needs to be dismantled and replaced during the construction process, which inevitably increases the construction investment cost.

[0003] In the prior art, there is also a retractable steel arch frame to replace the rigid steel arch frame. For example, the Chinese invention patent application publication number CN115306448A discloses a retractable tunnel support steel arch frame that adapts to the deformation of the surrounding rock. The steel arch frame structure uses the spring compression performance in the early stage to prevent the deformation pressure acting on the main structure of the steel arch frame from being too large. In the later stage, when the surrounding rock stress redistribution adjustment is completed, the spring rebound performance is used to make the main structure of the steel arch frame tightly combined with the surrounding rock to adapt to the appropriate deformation of the surrounding rock. Since the steel arch frame mainly relies on the deformation of the spring to absorb pressure and energy, this will lead to two problems. First, when the surrounding rock undergoes large deformation, the steel arch frame is subjected to large stress. When the stress is greater than the spring's bearing limit, the spring will be damaged and fail completely. Second, after the spring is deformed, an elastic stress will always appear in the steel arch frame, which makes the steel arch frame always in a state of high stress, which is not conducive to the long-term stable and effective support of the steel arch frame. Third, the above-mentioned retractable steel arch frame has weak deformation resistance and small deformation, and is only suitable for small deformation tunnels / tunnels. When the fault surrounding rock undergoes large dislocation movement, a single retractable steel arch frame is difficult to play an effective supporting role in the fault fracture zone surrounding rock large deformation disaster of over meters.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a three-level coordinated pressure-yielding energy-absorbing support system to at least solve the above-mentioned problems existing in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A three-level coordinated pressure-yielding energy-absorbing support system, the support system comprising pressure-yielding energy-absorbing anchor cables, primary support pressure-yielding arch frames and secondary lining steel arch frames, a plurality of pressure-yielding energy-absorbing anchor cables are all located at the periphery of the primary support pressure-yielding arch frames, and the primary support pressure-yielding arch frames are located at the periphery of the secondary lining steel arch frames;

[0008] The pressure-yielding energy-absorbing anchor cable is supported in the surrounding rock outside the initial support pressure-yielding arch frame;

[0009] The primary support pressure-yielding arch frame is composed of a plurality of steel units and a plurality of annular pressure-yielding devices, the annular pressure-yielding device is fixed between two adjacent steel units, the annular pressure-yielding device comprises an annular outer frame and an annular inner frame, one end of the annular inner frame extends into the annular outer frame, and the annular inner frame is guided and moved along the annular outer frame; an annular constant resistance sleeve is arranged on one of the annular outer frame and the annular inner frame, and an annular anchor cable is arranged on the other, one end of the annular anchor cable penetrates into the annular constant resistance sleeve, a constant resistance sliding body is arranged on the annular anchor cable penetrated into the annular constant resistance sleeve, and the constant resistance sliding body slides in the annular constant resistance sleeve with a constant resistance guide;

[0010] A plurality of radial pressure-releasing devices are arranged between the primary support pressure-releasing arch frame and the secondary lining steel arch frame, and the radial pressure-releasing devices include an upper baffle and a lower baffle, one of the upper baffle and the lower baffle is arranged close to the primary support pressure-releasing arch frame, and the other is arranged close to the secondary lining steel arch frame; a radial outer frame and a radial inner frame are arranged between the upper baffle and the lower baffle, one end of the radial inner frame extends into the radial outer frame, and the radial inner frame is guided to move along the radial outer frame; a radial inner sleeve is arranged on one of the radial outer frame and the radial inner frame, and a radial inner anchor cable is arranged on the other, one end of the radial inner anchor cable penetrates into the radial inner sleeve, and a sliding body is arranged on the radial inner anchor cable penetrated into the radial inner sleeve, and the sliding body is guided to slide in the radial inner sleeve with a constant resistance.

[0011] In the three-stage coordinated pressure-yielding energy-absorbing support system as described above, preferably, a plurality of radial outer anchor cables and a plurality of radial outer sleeves are further provided between the upper baffle plate and the lower baffle plate, and a sliding body is provided on one end of the radial outer anchor cable and inserted into the radial outer sleeve;

[0012] The plurality of radial outer sleeves are arranged in parallel on the same side of the radial outer frame, so that the radial outer sleeves are arranged in opposite directions to the radial inner sleeve; and the plurality of radial outer sleeves are evenly distributed on the periphery of the radial outer frame.

[0013] As described above, in the three-stage coordinated pressure-yielding energy-absorbing support system, preferably, the radial outer frame and the radial outer anchor cable are relatively fixedly connected via a connecting piece.

[0014] In the three-stage coordinated pressure-yielding energy-absorbing support system as described above, preferably, the radial inner frame is fixedly connected to the upper baffle, and the radial outer frame is fixedly connected to the lower baffle.

[0015] In the three-level coordinated pressure-yielding energy-absorbing support system as described above, preferably, the upper baffle is fixed on the primary support pressure-yielding arch frame, and the lower baffle is attached to the outside of the secondary lining steel arch frame;

[0016] The radial outer sleeve is fixed on the secondary lining steel arch frame.

[0017] The three-stage coordinated pressure-releasing energy-absorbing support system as described above is preferably provided with a protective tube outside the radial pressure-releasing device.

[0018] The three-level coordinated pressure-yielding energy-absorbing support system as described above is preferably configured to fill concrete between the primary support pressure-yielding arch frame and the secondary lining steel arch frame.

[0019] In the three-level coordinated pressure-yielding energy-absorbing support system as described above, preferably, a through hole is provided on each side of the top plate of the annular outer frame, and two through holes are respectively passed through the two side edges of the annular inner frame;

[0020] A through hole is respectively arranged on both sides of the top plate of the radial outer frame, and two through holes are respectively passed through the two side edges of the radial inner frame.

[0021] The three-stage coordinated pressure-yielding energy-absorbing support system as described above, preferably, the contact surfaces between the annular outer frame and the annular inner frame are both provided with a constant resistance friction structure, and the contact surfaces between the radial outer frame and the radial inner frame are both provided with a constant resistance friction structure;

[0022] The constant resistance friction structure is a regularly arranged triangular cross-section protrusion or rectangular cross-section protrusion, and the constant resistance friction structures on the outer support frame and the inner support frame are relatively staggered.

[0023] As described above, in the three-stage coordinated pressure-yielding energy-absorbing support system, preferably, the annular pressure-yielding device is arranged on the vertical edges on both sides of the primary support pressure-yielding arch frame, and a plurality of annular pressure-yielding devices are arranged on the vertical edges.

[0024] Beneficial effects:

[0025] In this support system, the pressure-yielding energy-absorbing anchor cable plays a basic supporting role, the circumferential pressure-yielding device can make the primary support pressure-yielding arch frame undergo constant resistance deformation in the circumferential direction, and the radial pressure-yielding device can make the primary support pressure-yielding arch frame and the secondary lining steel arch frame undergo relative dislocation movement, and the three-level pressure-yielding energy-absorbing structures cooperate with each other to adapt to the super-meter-level large deformation movement of the surrounding rock; ensure the integrity of the secondary lining structure and the tunnel clearance from intrusion; achieve better control of the super-meter-level large deformation caused by the surrounding rock deformation, and enhance the tunnel space deformation resistance capacity.

[0026] The three-level support system can stabilize the large deformation pressure of the surrounding rock, slowly perform the initial support to allow the compression arch frame to shrink, and reduce the possibility of damage to the compression arch frame locking structure due to strong impact pressure of displacement; and effectively control the compression pressure of the tunnel and the expansion rate and deformation size of the squeezing deformation of the tunnel surrounding rock, avoiding bending and breaking of the multi-level support structure due to excessive compression pressure. The three-level support system can better adapt to the deformation of the surrounding rock, and also ensure that the three-level support system always effectively plays a good supporting role, thereby improving the safety of the entire support system and helping to reduce economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting part of the present application are used to provide a further understanding of the invention. The exemplary embodiments and descriptions of the invention are used to explain the invention and do not constitute an improper limitation on the invention. Among them:

[0028] Figure 1 A schematic diagram of the structure of a support system for creating an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a pressure-absorbing energy-absorbing anchor cable according to an embodiment of the present invention;

[0030] Figure 3 A schematic structural diagram of an annular pressure relief device according to an embodiment of the present invention;

[0031] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0032] Figure 5 A schematic structural diagram of a radial pressure relief device according to an embodiment of the present invention;

[0033] Figure 6 The present invention provides an axial cross-sectional view of a tunnel when the surrounding rock is greatly deformed according to an embodiment of the present invention.

[0034] In the figure:

[0035] 1. Surrounding rock; 2. Pressure-yielding energy-absorbing anchor cable; 3. Initial support pressure-yielding arch frame; 4. Circumferential pressure-yielding device; 5. Radial pressure-yielding device; 6. Concrete; 7. Secondary lining steel arch frame; 8. Tunnel clearance;

[0036] 201, anchor clip; 202, anchor ring; 203, tray; 204, sliding body; 205, constant resistance sleeve; 206, steel strand; 207, resin anchoring agent;

[0037] 401, top plate of annular inner frame; 402, annular inner frame; 403, sleeve fixing seat; 404, annular anchor ring; 405, constant resistance sliding body; 406, annular constant resistance sleeve; 407, annular anchor cable; 408, annular anchor clip; 409, annular outer frame; 4010, bottom plate of annular outer frame;

[0038] 501, upper baffle; 502, radial inner frame; 503, radial inner anchor cable; 504, connecting piece; 505, radial outer anchor cable; 506, radial inner sleeve; 507, radial outer frame; 508, protective tube; 509, radial outer sleeve; 5010, lower baffle. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0040] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0042] According to the specific embodiments of the present invention, Figure 1-4 As shown, the present invention provides a three-level coordinated pressure-yielding energy-absorbing support system, the support system includes pressure-yielding energy-absorbing anchor cables 2, primary support pressure-yielding arch frames 3 and secondary lining steel arch frames 7, multiple pressure-yielding energy-absorbing anchor cables 2 are all located at the periphery of the primary support pressure-yielding arch frames 3, and the primary support pressure-yielding arch frames 3 are located at the periphery of the secondary lining steel arch frames 7.

[0043] The pressure-absorbing anchor cable 2 is supported in the surrounding rock 1 outside the initial support pressure-absorbing arch frame 3; in the present embodiment, the pressure-absorbing anchor cable 2 comprises an anchor clip 201, an anchor ring 202, a tray 203, a sliding body 204, a constant resistance sleeve 205, a steel strand 206 and a resin anchor 207; specifically, a hole is first drilled in the surrounding rock 1, and then the resin anchor 207 is placed at the bottom of the hole, and then the constant resistance sleeve 205 and the tray 203 are arranged at the hole mouth, and the sliding body 204, the anchor ring 202 and the anchor clip 201 are installed at the end of the steel strand 206 in sequence, and then the bottom end of the steel strand 206 is inserted into the resin anchor 206 at the bottom of the hole, and the steel strand 201 is stirred so that its end is anchored in the hole through the resin anchor 206, and at this time, one end of the steel strand 206 on which the sliding body 204 is installed is inserted into the constant resistance sleeve 205.

[0044] The primary support pressure-yielding arch frame 3 is assembled by multiple steel units and multiple annular pressure-yielding devices 4, the annular pressure-yielding device 4 is fixed between two adjacent steel units, the annular pressure-yielding device 4 includes an annular outer frame 409 and an annular inner frame 402, one end of the annular inner frame 402 extends into the annular outer frame 409, and the annular inner frame 402 is guided and moved along the annular outer frame 409; an annular constant resistance sleeve 406 is arranged on one of the annular outer frame 409 and an annular anchor cable 407 is arranged on the other, one end of the annular anchor cable 407 penetrates into the annular constant resistance sleeve 406, and a constant resistance sliding body 405 is arranged on the annular anchor cable 407 penetrated into the annular constant resistance sleeve 406, and the constant resistance sliding body 405 slides in the annular constant resistance sleeve 406 with constant resistance.

[0045] In this embodiment, both ends of the annular anchor cable 407 are fixed and limited by the annular anchor ring 404 and the annular anchor clip 408.

[0046] A plurality of radial pressure relief devices 5 are arranged between the primary support pressure relief arch frame 3 and the secondary lining steel arch frame 7. The radial pressure relief devices 5 include an upper baffle plate 501 and a lower baffle plate 5010. One of the upper baffle plate 501 and the lower baffle plate 5010 is arranged close to the primary support pressure relief arch frame 3, and the other is arranged close to the secondary lining steel arch frame 7. A radial outer frame 507 and a radial inner frame 502 are arranged between the upper baffle plate 501 and the lower baffle plate 5010. One end of the radial inner frame 502 extends into the radial outer frame. 507, and the radial inner frame 502 is guided to move along the radial outer frame 507; a radial inner sleeve 506 is provided on one of the radial outer frame 507 and a radial inner anchor cable 503 is provided on the other, one end of the radial inner anchor cable 503 penetrates into the radial inner sleeve 506, and a sliding body is provided on the radial inner anchor cable 503 penetrated into the radial inner sleeve 506, and the sliding body slides in the radial inner sleeve 506 with a constant resistance.

[0047] In the support system, the pressure-releasing energy-absorbing anchor cable 2 is used as the first-level pressure-releasing energy-absorbing structure, the annular pressure-releasing device 4 in the primary support pressure-releasing arch frame 3 is used as the second-level pressure-releasing energy-absorbing structure, and the radial pressure-releasing device 5 between the primary support pressure-releasing arch frame 3 and the secondary lining steel arch frame 7 is used as the third-level pressure-releasing energy-absorbing structure; wherein:

[0048] In the first-level pressure-absorbing energy-absorbing structure, the pressure-absorbing energy-absorbing anchor cable 2 arranged in the surrounding rock 1 plays a preliminary role in supporting the surrounding rock 1 of the tunnel.

[0049] In the second-level pressure-yielding energy-absorbing structure, when the surrounding rock 1 undergoes a small deformation, the surrounding rock 1 transmits pressure to the primary support pressure-yielding arch frame 3, and the primary support pressure-yielding arch frame 3 transmits the pressure received to the annular pressure-yielding device 4. Under the action of pressure, the annular inner frame 402 moves relative to the annular outer frame 409, so that the annular inner frame 402 retracts into the annular outer frame 409; the annular inner frame 402 drives the annular anchor cable 407 and the constant resistance sliding body 405 to move downward, and the constant resistance sliding body 405 and the annular constant resistance sleeve 406 produce constant resistance friction, which plays a constant resistance energy dissipation role; during the constant resistance deformation process of the annular pressure-yielding device 4, no large internal stress will be generated inside the annular pressure-yielding device 4, thereby ensuring that the arch frame can play a constant supporting role throughout the deformation process of the surrounding rock 1.

[0050] In the third-pole pressure-yielding energy-absorbing structure, when the surrounding rock 1 undergoes a large deformation of over a meter level, the surrounding rock 1 on both sides of the fault moves displaced with each other. At this time, the large deformation force of the surrounding rock 1 is transmitted to the radial pressure-yielding device 5. The radial outer frame 507 and the radial inner frame 502 in the radial pressure-yielding device 5 are relatively displaced under the action of pressure, and the radial inner frame 502 retracts into the radial outer frame 507. The radial outer frame 507 and the radial inner frame 502 convert the pressure they receive into a pulling force on the radial inner sleeve 506 and the radial inner anchor cable 503, so that the sliding body radial inner sleeve 506 has a constant resistance friction, which plays a constant resistance energy dissipation role.

[0051] That is, the pressure-absorbing anchor cable 2 plays a basic supporting role, the circumferential pressure-yielding device 4 can cause the primary support pressure-yielding arch frame 3 to undergo constant resistance deformation in the circumferential direction, and the radial pressure-yielding device 5 can cause the primary support pressure-yielding arch frame 3 and the secondary lining steel arch frame 7 to undergo relative dislocation movement, and the three-level pressure-yielding energy-absorbing structures cooperate with each other to adapt to the super-meter-level large deformation movement of the surrounding rock 1; ensure the integrity of the secondary lining structure and the tunnel clearance 8 is not invaded; achieve better control of the super-meter-level large deformation caused by the deformation of the surrounding rock 1, and enhance the deformation resistance of the tunnel space.

[0052] Moreover, the three-level support system can stabilize the large deformation pressure of the surrounding rock 1, slowly perform the initial support to allow the compression arch frame 3 to shrink, and reduce the possibility of damage to the compression arch frame locking structure due to the strong impact pressure of the displacement; and effectively control the tunnel compression pressure and the expansion rate and deformation size of the extrusion deformation of the tunnel surrounding rock 1, avoiding the bending and breaking of the multi-level support structure due to excessive compression pressure, so that the three-level support system can better adapt to the deformation of the surrounding rock 1, and also ensure that the three-level support system always effectively plays a good supporting role, thereby improving the safety of the entire support system and helping to reduce economic losses.

[0053] A plurality of radial outer anchor cables 505 and a plurality of radial outer sleeves 509 are also arranged between the upper baffle plate 501 and the lower baffle plate 5010. A sliding body is arranged on one end of the radial outer anchor cable 505 and inserted into the radial outer sleeve 509. The plurality of radial outer sleeves 509 are arranged side by side on the same side as the radial outer frame 507 so that the radial outer sleeves 509 and the radial inner sleeve 506 are arranged in opposite directions. The plurality of radial outer sleeves 509 are evenly distributed on the periphery of the radial outer frame 507.

[0054] In one embodiment of the present application, at least two sets of radial outer anchor cables 505 and radial outer sleeves 509 are evenly distributed on the periphery of the radial outer frame 507, and the radial outer sleeve 509 and the radial inner sleeve 506 are arranged in opposite directions, so that the sliding body in the radial outer sleeve 509 and the sliding body in the radial inner sleeve 506 move in opposite directions, thereby making the initial support pressure-relieving arch frame 3 have the ability of bidirectional constant resistance pressure-relieving.

[0055] In this embodiment, both ends of the radially outer anchor cable 505 and the radially inner anchor cable 503 are fixed and limited by anchor rings and anchor clips, which will not be described in detail here.

[0056] The radial outer frame 507 and the radial outer anchor cable 505 are relatively fixedly connected via a connector 504. In one embodiment of the present application, the connector 504 may be a profiled steel structure, and the two ends of the connector 504 are respectively welded and fixed to the radial outer anchor cable 505 and the radial outer frame 507, so that the radial outer anchor cable 505 and the radial outer frame 507 can achieve synchronous movement.

[0057] The radial inner frame 502 is fixedly connected to the upper baffle 501, and the radial outer frame 507 is fixedly connected to the lower baffle 5010. In one embodiment of the present application, the top plate of the radial inner frame 502 is fixed to the upper baffle 501, and the bottom plate of the radial outer frame 507 is fixed to the lower baffle 5010.

[0058] The upper baffle plate 501 is fixed on the primary support pressure arch frame 3, and the lower baffle plate 5010 is attached to the outside of the secondary lining steel arch frame 7; the radial outer sleeve 509 is fixed on the secondary lining steel arch frame 7.

[0059] In one embodiment of the present application, the lower baffle 5010 is only attached to the outside of the second lining steel arch frame 7, and is not directly fixed to the second lining steel arch frame 7, while the radial outer sleeve 509 is fixed to the second lining steel arch frame 7, so that the lower baffle 5010 can move relative to the radial outer sleeve 509, which is convenient for the two-way pressure relief of the radial pressure relief device 5, specifically:

[0060] When the surrounding rock 1 undergoes a large deformation exceeding the meter level, the surrounding rock 1 on both sides of the fault displaces relative to each other, and the primary support yielding arch frame 3 is subjected to a large stress, causing the primary support yielding arch frame 3 to undergo a large displacement relative to the secondary lining steel arch frame 7 along the deformation direction of the surrounding rock 1. One side of the primary support yielding arch frame 3 approaches the secondary lining steel arch frame 7, causing the radial yielding device 5 to be compressed, and the other side of the primary support yielding arch frame 3 moves away from the secondary lining steel arch frame 7, causing the radial yielding device 5 to be stretched. Therefore, on the basis of eliminating the large deformation exceeding the meter level of the surrounding rock 1, the secondary lining steel arch frame 7 can be kept in place as much as possible, thereby ensuring the safety and stability of the tunnel clearance 8 as much as possible.

[0061] Among them, when the radial pressure-relieving device 5 is compressed, the upper baffle plate 501 is subjected to the pressure of the initial support pressure-relieving arch frame 3, and the upper baffle plate 501 moves inward toward the lower baffle plate 5010. At this time, the annular inner frame 402 moves toward the annular outer frame 409, and the annular constant resistance sleeve 406 and its matching constant resistance sliding body 405 play a constant resistance pressure-relieving role to adapt to one side of the initial support pressure-relieving arch frame 3 moving toward the secondary lining steel arch frame 7.

[0062] When the radial pressure-relieving device 5 is stretched, the upper baffle plate 501 is subjected to the pulling force of the initial support pressure-relieving arch frame 3, and the upper baffle plate 501 moves outward in the direction of the principle lower baffle plate 5010. At this time, the upper baffle plate 501 drives the radial outer anchor cable 505 to move outward, so that the radial constant resistance sleeve and its matching sliding body play a constant resistance pressure-relieving role to adapt to the other side of the initial support pressure-relieving arch frame 3 moving away from the second lining steel arch frame 7; in this process, the radial outer anchor cable 505 drives the radial outer frame 507 to move synchronously through the connecting piece 504, so as to maintain the relative stability between the radial outer frame 507 and the radial inner frame 502.

[0063] In summary, the radial pressure-releasing device 5 has a bidirectional pressure-releasing effect, so that the support system can better adapt to the large deformation of the surrounding rock 1.

[0064] A protective tube 508 is provided outside the radial pressure-releasing device 5. In one embodiment of the present application, the protective tube 508 can be made of materials such as engineering plastics or iron sheets, and the protective tube 508 is used to prevent debris from invading the radial pressure-releasing device 5, thereby ensuring the effectiveness of the radial pressure-releasing device 5.

[0065] Concrete 6 is filled between the primary support yield arch frame 3 and the secondary lining steel arch frame 7. In one embodiment of the present application, concrete 6 of a certain strength is filled between the primary support yield arch frame 3 and the secondary lining steel arch frame 7 to play a better comprehensive support role; wherein the protective tube 508 sleeved on the outside of the radial yield device 5 can prevent the intrusion of concrete; in this embodiment, foam concrete can be filled within a certain range outside the radial yield device 5, which can prevent the foam concrete from being weak in strength and easy to deform when the primary support yield arch frame 3 and the secondary lining steel arch frame 7 are relatively displaced, thereby ensuring that the foam concrete around the radial yield device 5 will not have a significant impact on the radial yield device 5, and providing sufficient deformation space for the radial yield device 5.

[0066] A through hole is provided on each side of the top plate of the annular outer frame 409, and two through holes are respectively passed through the two side edges of the annular inner frame 402; a through hole is provided on each side of the top plate of the radial outer frame 507, and two through holes are respectively passed through the two side edges of the radial inner frame 502. In one embodiment of the present application, the two side edges of the annular inner frame 402 are guided to move along the through holes of the top plate of the annular outer frame 409 to ensure that the annular inner frame 402 moves more stably relative to the annular outer frame 409; the two side edges of the radial inner frame 502 are guided to move along the through holes of the top plate of the radial outer frame 507 to ensure that the radial inner frame 502 moves more stably relative to the radial outer frame 507.

[0067] A constant resistance friction structure is arranged on the contact surface between the annular outer frame 409 and the annular inner frame 402, and a constant resistance friction structure is arranged on the contact surface between the radial outer frame 507 and the radial inner frame 502; the constant resistance friction structure is a regularly arranged triangular cross-section protrusion or rectangular cross-section protrusion, and the constant resistance friction structures on the outer support frame and the inner support frame are relatively staggered.

[0068] In one embodiment of the present application, the triangular cross-section protrusion or the rectangular cross-section protrusion can not only increase the friction force between the outer frame and the inner frame, but also when the outer frame and the inner frame are relatively stationary, the protrusions on the outer frame and the inner frame are aligned with each other, which can provide stability for the outer frame and the inner frame when they are relatively stationary.

[0069] The annular pressure-releasing device 4 is arranged on the vertical edges on both sides of the primary support pressure-releasing arch frame 3, and multiple annular pressure-releasing devices 4 are arranged on the vertical edges. In one embodiment of the present application, the annular pressure-releasing device 4 is located in the vertical edge of the primary support pressure-releasing arch frame 3, so that the primary support pressure-releasing arch frame 3 can transfer the pressure of the surrounding rock 1 to the annular pressure-releasing device 4, so that the annular pressure-releasing device 4 converts the pressure received into a pulling force between the constant resistance sleeve and the anchor cable, so that the annular pressure-releasing device 4 can better play its constant resistance pressure-releasing role. Two annular pressure-releasing devices 4 are arranged on the vertical edge of the primary support pressure-releasing arch frame 3, and the pressure-releasing stroke of each annular pressure-releasing device 4 is the stroke that the outer frame and the inner frame can be relatively displaced. Each additional annular pressure-releasing device 4 in the primary support pressure-releasing arch frame 3 adds a pressure-releasing stroke to the primary support pressure-releasing arch frame 3, thereby improving the ability of the primary support pressure-releasing arch frame 3 to adapt to the deformation of the surrounding rock 1.

[0070] In this embodiment, a sleeve fixing seat 403 is provided on the top plate of the annular outer frame 409, the annular constant resistance sleeve passes through the annular outer frame 409 and is fixed on the sleeve fixing seat 403, and the annular inner frame top plate 401 and the annular outer frame bottom plate 4010 are used to connect between the steel units of the initial support pressure arch frame 3.

[0071] In this embodiment, reinforcement plates are obliquely arranged on the inner sides of the bottoms of the annular inner frame 402 and the radial inner frame 502. The obliquely arranged reinforcement plates are arranged in pairs, and avoidance holes are arranged on the reinforcement plates for the anchor cable to pass through, so as to improve the structural strength of the inner frame.

[0072] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A three-level coordinated pressure-yielding energy-absorbing support system, characterized in that: The support system includes pressure-yielding energy-absorbing anchor cables, primary support pressure-yielding arch frames and secondary lining steel arch frames, wherein a plurality of pressure-yielding energy-absorbing anchor cables are all located at the periphery of the primary support pressure-yielding arch frames, and the primary support pressure-yielding arch frames are located at the periphery of the secondary lining steel arch frames; The pressure-yielding energy-absorbing anchor cable is supported in the surrounding rock outside the initial support pressure-yielding arch frame; The primary support pressure-yielding arch frame is composed of a plurality of steel units and a plurality of annular pressure-yielding devices, the annular pressure-yielding device is fixed between two adjacent steel units, the annular pressure-yielding device comprises an annular outer frame and an annular inner frame, one end of the annular inner frame extends into the annular outer frame, and the annular inner frame is guided and moved along the annular outer frame; an annular constant resistance sleeve is arranged on one of the annular outer frame and the annular inner frame, and an annular anchor cable is arranged on the other, one end of the annular anchor cable penetrates into the annular constant resistance sleeve, a constant resistance sliding body is arranged on the annular anchor cable penetrated into the annular constant resistance sleeve, and the constant resistance sliding body slides in the annular constant resistance sleeve with a constant resistance guide; A plurality of radial pressure-releasing devices are arranged between the primary support pressure-releasing arch frame and the secondary lining steel arch frame, and the radial pressure-releasing devices include an upper baffle and a lower baffle, one of the upper baffle and the lower baffle is arranged close to the primary support pressure-releasing arch frame, and the other is arranged close to the secondary lining steel arch frame; a radial outer frame and a radial inner frame are arranged between the upper baffle and the lower baffle, one end of the radial inner frame extends into the radial outer frame, and the radial inner frame is guided to move along the radial outer frame; a radial inner sleeve is arranged on one of the radial outer frame and the radial inner frame, and a radial inner anchor cable is arranged on the other, one end of the radial inner anchor cable penetrates into the radial inner sleeve, and a sliding body is arranged on the radial inner anchor cable penetrated into the radial inner sleeve, and the sliding body is guided to slide in the radial inner sleeve with a constant resistance.

2. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 1 is characterized in that: A plurality of radial outer anchor cables and a plurality of radial outer sleeves are also arranged between the upper baffle plate and the lower baffle plate, and a sliding body is arranged on one end of the radial outer anchor cable and inserted into the radial outer sleeve; The plurality of radial outer sleeves are arranged in parallel on the same side of the radial outer frame, so that the radial outer sleeves are arranged in opposite directions to the radial inner sleeve; and the plurality of radial outer sleeves are evenly distributed on the periphery of the radial outer frame.

3. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 2 is characterized in that: The radial outer frame and the radial outer anchor cable are relatively fixedly connected via a connecting piece.

4. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 3 is characterized in that: The radial inner frame is fixedly connected to the upper baffle, and the radial outer frame is fixedly connected to the lower baffle.

5. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 4 is characterized in that: The upper baffle is fixed on the primary support pressure arch frame, and the lower baffle is attached to the outside of the secondary lining steel arch frame; The radial outer sleeve is fixed on the secondary lining steel arch frame.

6. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 5 is characterized in that: A protective tube is arranged outside the radial pressure relief device.

7. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 6 is characterized in that: Fill concrete between the primary support compression arch frame and the secondary lining steel arch frame.

8. The three-level coordinated pressure-yielding energy-absorbing support system according to any one of claims 1 to 7, characterized in that: The top plate of the annular outer frame is provided with a through hole on each side, and the two sides of the annular inner frame are respectively penetrated by two through holes; A through hole is respectively arranged on both sides of the top plate of the radial outer frame, and two through holes are respectively passed through the two side edges of the radial inner frame.

9. The three-level coordinated pressure-yielding energy-absorbing support system according to claim 8 is characterized in that: The contact surfaces between the annular outer frame and the annular inner frame are both provided with a constant resistance friction structure, and the contact surfaces between the radial outer frame and the radial inner frame are both provided with a constant resistance friction structure; The constant resistance friction structure is a regularly arranged triangular cross-section protrusion or rectangular cross-section protrusion, and the constant resistance friction structures on the outer support frame and the inner support frame are relatively staggered.

10. The three-level coordinated pressure-yielding energy-absorbing support system according to any one of claims 1 to 7, characterized in that: The annular pressure-releasing device is arranged on the vertical edges on both sides of the primary support pressure-releasing arch frame, and a plurality of annular pressure-releasing devices are arranged on the vertical edges.

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